Ofcom has closed the first and most significant round of bidding in the complex auction of airwaves being sold to support 4G services, and is expected to reveal the results this week.

The announcement should provide a much-needed boost to the Treasury after some industry insiders said that bidding had proved to be higher than expected.

The sale of the 4G spectrum is expected to raise up to £3.5 billion for the Treasury as the seven bidders jostle for position, but a fierce bidding process could push the proceeds towards the £4 billion mark.